Load Transfer during Turn
- Caleb Nebiyou Mengistu
Slip Angle:
First and foremost, the weight that is exerted onto a car’s tire deforms the wheel. When the car undergoes a turn, the deformation will angle itself further in, influencing the steering angle. This phenomena is called a slip angle, and is represented in the diagram below:
Combining this with an understanding of the bicycle/Ackermann steering model, you can determine the slip angles a car when it is going under a turn. The videos below go over important concepts for calculating slip angles.
Tire Modelling: Vehicle Dynamics & Control - 07 Tires: Terminology and basics Vehicle Dynamics & Control - 08 Lateral tire models
Bicycle Model: Vehicle Dynamics & Control - 09 Dynamic bicycle model with linear tires
Slip Angle: Vehicle Dynamics & Control - 11 Oversteer and understeer Vehicle Dynamics & Control - 12 Understeer gradient Vehicle Dynamics & Control - 13 Yaw stability
Before going into load transfer, you must do complete the hand calculations for slip angle, and create a MATLAB calculator.
Load Transfer
When a car undergoes a turn, the weight of the car shifts, and the load is transferred towards the outer wheels based off the centrifugal force of the car.
Your task is to determine how the centrifugal force will shift the weight of the car onto each tire. Important things to consider is location of center of gravity, tangential velocity, turning radius, wheelbase and track. Use info from the slides below for extra reference: